Transmission Parts

Browse all Sonnax transmission parts here, or use the filters below to find just what you are looking for.

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U151E • U151F • U250E

O-Ringed End Plug Kit 27741-20K

Helps cure:

Inconsistent shift quality
Flare shifts
Clutch failure
Bump shifts
Bang shifts
Shift codes

Powerglide

High Clutch Hub Wear Plate 28755-06

Small

Material: Case-Hardened Steel

Powerglide

Heavy Duty Planetary Rebuild Kit 28922-01HDK

For 1.76-style planetary

Powerglide

Servo Piston Kit 28821-02K

Dual-seal design, PTFE sealing ring style

Powerglide

Servo Cover Kit 28821-03K

Purple anodized

4L80-E • 4L85-E

Boost Valve Kit 34200-01K

O-Ring style. Kit can be retrofit to back to '89 units. See instructions for details.

Helps cure:

Uncontrollable line rise
High line pressure
Broken parts
Broken clutch piston

TH350 • TH350C

Intermediate Servo Sleeve Kit 35709-01K

Helps cure:

No engine braking in manual 2nd
Low line pressure in Reverse
Low line pressure in Neutral
Low line pressure in Drive
Delayed engagement

01J

Oversized Clutch Control (KSV) Valve Kit 33741B-03K

With flow notches

Helps cure:

Chatter on Forward
Chatter on Reverse
Clutch friction failure & overheat

01J

Oversized VSTV Pilot Pressure Valve 33741B-06

Helps cure:

Delayed engagement
Chatter on acceleration
Adaptive limit codes
Unstable solenoid pressure

01J • 01T

Oversized Safety Valve 33741B-01

Helps cure:

Delayed Forward
Chatter on Forward
Harsh Forward

4L80-E • 4L85-E • TH400 • TH425

Forward Clutch Hub Front Washer 34298-078

Material: Steel
Thickness: 0.078"
Outer Dia.: 1.781"
Inner Dia.: 1.289"

Helps cure:

Excess front endplay

4L80-E • 4L85-E

Low/Reverse Servo Spacer Kit 34528-01K

Fits '96-later.

Helps cure:

Broken Low/Reverse servo piston
No Reverse

TH400 • TH425

Boost Valve Kit 34910-01K

O-Ring Style

Helps cure:

Low line rise
1-2 Soft
2-3 Soft
Delayed Reverse
Reverse shudder

C6 Elevated Pressure Main Pressure Regulator Spring 36946-13

C6

Elevated Pressure Main Pressure Regulator Spring 36946-13

Calibrated to OE gas line pressure, fits gas/diesel

Helps cure:

Soft shifts
Poor shift quality
Low base line pressure
High line pressure

46RE • 46RH • 47RE • 47RH • 48RE

Rear (Forward) Clutch Inner Lip Seal 3647-01

Material: Viton®
Seal Style: Solid
Height: 0.180"
Width: 0.515"
Outer Dia.: 2.300"

Helps cure:

Delayed Forward
Delayed engagement
Burnt Forward clutch

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